时间：12月12日（周四）10:00-11:00

地点：北京大学经济学院302

主讲人：Chang Liu (Lecturer in Economics of the UNSW Business School)

主持老师：吴泽南，石凡奇（经院）；胡岠（国发院）

参与老师：胡涛，吴泽南，石凡奇（经院）；汪浩，胡岠，邢亦青（国发院）；翁翕，刘烁（光华）

题目: Robust Contracts with Exploration

摘要：We study a two-period moral hazard problem; there are two agents, with action sets that are unknown to the principal. The principal contracts with each agent sequentially, and seeks to maximize the worst-case discounted sum of payoffs, where the worst case is over the possible action sets. The principal observes the action chosen by the first agent, and then offers a new contract to the second agent based on this knowledge, thus having the opportunity to explore in the first period. We introduce and compare three different notions of dynamic worst-case considerations. Within each notion, we define a suitable rule of updating and characterize the principal's optimal payoff guarantee. We find that linear contracts are robustly optimal not only in static settings, but also in dynamic environments with exploration.

主讲人介绍：Chang Liu is a Lecturer in Economics at the UNSW Business School. His research is primarily in pure and applied microeconomic theory. He is particularly focused on the equilibrium behavior and the design of mechanisms in settings where dynamic considerations are significant features of the environment. Prior to joining UNSW, he was a Postdoctoral Fellow at the Simons Laufer Mathematical Sciences Institute (SLMath, formerly MSRI). He holds a Ph.D. in Economics from Harvard University.

微观理论工作坊

时间：12月12日（周四）11:10-12:10

地点：北京大学经济学院302

主讲人：陈彦琳（南京审计大学社会与经济研究院助理教授）

主持老师：吴泽南，石凡奇（经院）；胡岠（国发院）

参与老师：胡涛，吴泽南，石凡奇（经院）；汪浩，胡岠，邢亦青（国发院）；翁翕，刘烁（光华）

题目: Influencer Networks

摘要：This paper develops a model to examine the formation of influencer networks in user-generated content markets. Unlike previous research, we find that every strict equilibrium network exhibits a nested, upward-linking structure where multiple levels of influencers can coexist. Moreover, across a broad range of parameters, all payoff dominant strict equilibria conform to the law of the vital few: regardless of the population size, a small but significant group of players provides all content. We also establish a link between efficiency and equilibrium, and shows that all efficient strategy profiles are strict equilibria of an auxiliary game with larger benefit parameters. For sufficiently large populations, a single nested upward-linking network connecting all players can emerge, despite potentially polarized tastes over content categories.

主讲人介绍：陈彦琳，南京审计大学社会与经济研究院助理教授。研究领域为微观经济理论、产业组织理论、实验经济学等，主要研究方向包括机制设计、信息设计、市场设计、知情委托人、逆向选择、网络经济、数字经济等。在The Econmic Journal、Games and Economic Behavior等国际顶尖期刊发表论文，主持国家自然科学基金青年项目。报告人长期致力于微观经济理论、产业组织理论和实验经济学的研究，尤其在机制设计、信息设计、市场设计等领域取得了突出成果。其研究聚焦于网络经济和数字经济的理论前沿，分析了现代经济中的核心问题，如知情委托人、逆向选择等。